Audio/Control Head; Tape Running Adjustment - JVC HR-XVC1U Service Manual

2-2: CONFIRMATION AND ADJUSTMENT OF AUDIO/
CONTROL HEAD
When the Tape Running Mechanism does not work well,
adjust the following items.
1. Playback the VHS Alignment Tape (MHP).
2. Confirm that the reflected picture of stamp mark is
appeared on the tape prior to P4 Post as shown in Fig. 2-
2-A.
a) When the reflected picture is distorted, turn the screw
1 clockwise until the distortion is disappeared.
b) When the reflected picture is not distorted, turn the
screw 1 counterclockwise until little distortion is
appeared, then adjust the a).
Turn the screw 2 to set the audio level to maximum.
3.
4. Confirm that the bottom of the Audio/ Control Head and
the bottom of the tape is shown in Fig. 2-2-C.
When the height is not correct, turn the screw 3 to
c)
adjust the height. Then, adjust the 1~3 again.

Audio/Control Head

Audio/Control Head
3
2
Audio/Control Head
Tape
1-22
MECHANICAL ADJUSTMENTS
Reflected picture of
Stamp Mark
P4 Cap
Stamp Mark
Fig. 2-2-A
1
4
Fig. 2-2-B
0.25±0.05mm
Fig. 2-2-C

2-3: TAPE RUNNING ADJUSTMENT

(X VALUE ADJUSTMENT)
1. Confirm and adjust the position of the Tension Post.
(Refer to item 1-1)
2. Adjust the Guide Roller. (Refer to item 2-1)
3. Confirm and adjust the Audio/Control Head.
(Refer to item 2-2)
4. Connect CH-1 of the oscilloscope to TP3002, CH-2 to
TP101 and CH-3 to HOT side of Audio Out Jack.
5. Playback the VHS Alignment Tape (MHP).
6. Press and hold the Tracking-Auto button on the remote
control more than 2 seconds to set tracking to center.
7. Set the X Value adjustment driver (X-JG153) to the 4 of
Fig. 2-2-B. At first, turn the Audio/Control Head position
fully toward the capstan side. Then adjust X Value to turn
it back gradually toward the cylinder side and stop on the
second peak point position of the envelope.
Play MHP
Drum side Control head position
8. Perform tracking operation and confirm the envelope is
maximum on the tracking center position.
9. Playback the VHS Alignment Tape (MHP-L).
10. Perform tracking operation and confirm the envelope is
maximum on the tracking center position. If envelop is not
maximum, should be fine-tune the X-VALUE.
Play MHP-L
X-value adjustment point
Capstan side
Maximum Fig. 2-3